"My husband is in love with another woman," is something you never imagined you'd hear yourself saying. He's cheated on you and now he tells you that it wasn't just about physical intimacy at all. He's developed feelings for the other woman and he's not sure what he wants for his future. Your life is in limbo and your heart is broken. Not only do you have to absorb the fact that he was unfaithful you also have to face the reality that his feelings don't just belong to you anymore. If he's not sure who he wants and you two have yet to decide to separate or divorce, there is still time to mend the relationship and get him back in love with only you.
If your husband is in love with another woman you can't ignore that fact. He's fallen for her and that makes his infidelity much more serious than if he was simply looking for something physical. He cares for the other woman and unless you handle this in just the right way, he'll likely leave you for her. Getting upset is understandable but can be damaging to the situation. He likely feels badly that this has happened but he also feels entitled to his feelings. Right now, a relationship with her may seem or feel much more alluring than staying in his marriage to you.
Try to be as calm as possible when you talk to him about her. It's obviously going to be incredibly painful so asking for details about what she's like or what she has that you don't have, isn't going to help. Most men who have affairs aren't comparing the two women in their minds. They aren't in search of someone who is younger, thinner or prettier. They simply are drawn into something with someone who offers them validation or makes them feel needed or wanted.
If you can carry yourself with dignity and self confidence through this that will impact your husband.
In most cases when a man believes he has fallen in love with his mistress, that dream comes to a screeching halt once he realizes what he may lose at home. If you stay strong and focus on your own future happiness, your husband will be drawn back towards you. He'll remember why he married you and that other woman won't seem nearly as appealing anymore.